title: Labeling of islet cells with iron oxide nanoparticles through DNA hybridization for highly sensitive detection by MRI.
abstract: A labeling method for islet cells with superparamagnetic iron oxide nanoparticles (SPIOs) based on DNA hybridization is proposed for monitoring of transplanted islets by magnetic resonance imaging (MRI). The surfaces of SPIOs were modified by via Michael reaction by reacting oligo-(deoxyadenylic acid)-bearing a terminal thiol group at the 5'-end ((dA)20-SH) with maleic acid functional groups on the SPIOs. The SPIOs were immobilized on islet cells which had been pretreated with oligo-(thymidylic acid)-poly(ethylene glycol)-phospholipid conjugates ((dT)20-PEG-DPPE) through DNA hybridization. Transmission electron microscopy observations revealed that SPIOs were initially anchored on the islet cell surfaces and subsequently transferred to endosomes or exfoliated with time. The SPIO-labeled islet cells could be clearly detected as dark spots by T2(*)-weighted MR image, whereas non-labeled islet cells could not be detected.
authors.affiliation: Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Narufumi
authors.initials: N
authors.lastname: Kitamura
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Nakai
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Kohda
authors.forename: Keiko
authors.initials: K
authors.lastname: Furuta-Okamoto
authors.forename: Hiroo
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003287:Contrast Media / Q000737:chemistry* / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D007515:Islets of Langerhans / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000378:metabolism; D016381:Islets of Langerhans Transplantation; D008279:Magnetic Resonance Imaging; D008297:Male; D008298:Maleates / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D009693:Nucleic Acid Hybridization; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D013938:Thymidine Monophosphate / Q000737:chemistry
chemical_list: D003287:Contrast Media; D004277:DNA, Single-Stranded; C102564:DPPE-PEG2000; D005290:Ferric Compounds; D008298:Maleates; D010714:Phosphatidylethanolamines; C000499:ferric oxide; D013938:Thymidine Monophosphate; D011092:Polyethylene Glycols; C030272:maleic acid
keywords: Contrast agent; DNA hybridization; Islet; MRI; SPIO; Surface modification; ssDNA–PEG–phospholipid conjugates